Hello, I need a little help with an intermittent idle surging issue. Just finished up the build, street port with power FC. It has already been professionally tuned as well. It runs beautiful, but I have a very annoying idle surge...so far it will only surge when it is at operating temp while driving, or at a hot start. It will surge from 1.5k RPM to 2.5k RPM. This condition will occur WITH OR WITHOUT the IAC valve connected. I have not made any adjustments to the idle screws. Any help or direction on this issue would be greatly appreciated! Thanks guys!


http://www.youtube.com/watch?v=Ix8mH...&feature=g-upl

 

Did you remove the 3 wires from the ECU connector? One is for EGR and the other two are for something else that the PFC doesn't control. I'm sorry, I can't remember. Mine did the same thing until I clipped those wires. After that, it idled perfectly.

 

Thank you for the info Funkspectrum! I have not removed any wires from the ECU connector. I will search around to find the specific 3 wires I need to remove, or if anyone knows I would appreciate the information. Connector and pinout information would be great!

 

I think you can find it in the Dale Clark PFC writeup.

http://www.clubrx.org/media/pfc/PowerFC_FAQ.pdf


I was also mistaken...It's 4 wires.

 

I have an identical situation to yours. Street port, power fc, professionally tuned at Neptune speed in huntington beach Ca. When I turn on my ac sometimes it will surge, turn it off an on it goes away. Today I was backing out of the driveway and when stepping on the brakes it started surging. Very random and I have no idea why. I cut the pins off the ecu so I didn't have to hack up my harness.

 

Thank you Funkspectrum, there is lots of great information in that write up! For anyone that is having the same problem see the attached picture for pin removal information. I will let you know how it goes!

Linnadwag, so you still have the idle surge even after you cut the 4 pins to the ECU? After driving around today it seems to get the idle surge after driving it hard for a few minutes...very annoying! Then I would cruise light throttle for a few minutes and the surge would go away.

 

Yes sir. Pins cut from power fc. It surged before and after I did the A/C relay mod so my ac would work on all blower speeds. My idle screw under the throttle is all the way in and I'm idling around 750+. I have no thermowax unit. I'm gonna check my TPS settings to see if they're a hair off. Had the manifold off more then a few times.

 

 

Had the same problem and Dale instructed me to turn off the O2 sensor feedback using the commander. Once done, rolling idle disappeared.

 

How do you do this?

 

Turn on your PFC, select ETC. , then scroll down to Function Select. Under this menu you will see item 4 is O2 F/B Control. Next to each item item under the Function Select menu is a Japanese symbol. They should all be the same. The default setting is for all of these to be "on". Select the symbol next to the O2 F/B Control item and it changes to another symbol that represents "off". Now the O2 feedback is turned off.

 

This doesn't work for everyone. I had mine on and my idle was rock solid.